全文获取类型
收费全文 | 15578篇 |
免费 | 637篇 |
国内免费 | 145篇 |
专业分类
化学 | 10126篇 |
晶体学 | 52篇 |
力学 | 323篇 |
综合类 | 1篇 |
数学 | 2936篇 |
物理学 | 2922篇 |
出版年
2023年 | 141篇 |
2022年 | 290篇 |
2021年 | 351篇 |
2020年 | 420篇 |
2019年 | 496篇 |
2018年 | 380篇 |
2017年 | 291篇 |
2016年 | 598篇 |
2015年 | 566篇 |
2014年 | 551篇 |
2013年 | 917篇 |
2012年 | 1080篇 |
2011年 | 1282篇 |
2010年 | 682篇 |
2009年 | 565篇 |
2008年 | 909篇 |
2007年 | 835篇 |
2006年 | 840篇 |
2005年 | 774篇 |
2004年 | 605篇 |
2003年 | 471篇 |
2002年 | 438篇 |
2001年 | 242篇 |
2000年 | 172篇 |
1999年 | 182篇 |
1998年 | 155篇 |
1997年 | 164篇 |
1996年 | 168篇 |
1995年 | 145篇 |
1994年 | 115篇 |
1993年 | 102篇 |
1992年 | 88篇 |
1991年 | 76篇 |
1990年 | 64篇 |
1989年 | 41篇 |
1988年 | 45篇 |
1987年 | 47篇 |
1986年 | 45篇 |
1985年 | 71篇 |
1984年 | 59篇 |
1983年 | 34篇 |
1982年 | 59篇 |
1981年 | 49篇 |
1980年 | 44篇 |
1979年 | 42篇 |
1978年 | 45篇 |
1977年 | 42篇 |
1976年 | 51篇 |
1974年 | 37篇 |
1973年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
In the Higgs phase we may be left with a residual finite symmetry groupH of the condensate. The topological interactions between the magnetic and electric excitations in these so-called discreteH gauge theories are completely described by the Hopf algebra or quantum groupD(H). In 2+1 dimensional space time we may add a Chern-Simons term to such a model. This deforms the underlying Hopf algebraD(H) into the quasi-Hopf algebraD
(H) by means of a 3-cocycle onH. Consequently, the finite number of physically inequivalent discreteH gauge theories obtained in this way are labelled by the elements of the cohomology groupH
3(H,U(1)). We briefly review the above results in these notes. Special attention is given to the Coulomb screening mechanism operational in the Higgs phase. This mechanism screens the Coulomb interactions, but not the Aharonov-Bohm interactions.Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 98. No. 3, pp. 509–523, March, 1994 相似文献
72.
Alexander Koldobsky 《Journal of Theoretical Probability》1994,7(1):135-145
Let μ be a measure in a Banach spaceE, f be an even function onR. We consider the potentialg(a)=f E f(‖x?a‖)dμ(x). The question is as follows: For whichf does the potentialg determine μ uniquely? In this article we give answers in the cases whereE=l ∞ n and wheref(t)=|t| p andE is a finite dimensional Banach space with symmetric analytic norm. Calculating the Fourier transform of the functionf(‖x‖ ∞) we give a new proof of the J. Misiewicz's result that the functionf(‖x‖ ∞) is positive definite only iff is a constant function. 相似文献
73.
Yeong E. Kim Alexander L. Zubarev 《International Journal of Theoretical Physics》1994,33(9):1861-1867
For astrophysical calculations, it is customary to extrapolate higher-energy (20keV) data using the Gamow transmission coefficient in estimating the nonresonance nuclear fusion reaction cross sections (E) for charged particles at low energies (<20 keV). We present a general extrapolation method based on a more realistic Coulomb barrier transmission coefficient, which can accommodate simultaneously both nonresonance and resonance contributions. 相似文献
74.
Acosta D Athanas M Masek G Paar H Bean A Gronberg J Kutschke R Menary S Morrison RJ Nakanishi S Nelson HN Nelson TK Richman JD Ryd A Tajima H Schmidt D Sperka D Witherell MS Procario M Yang S Balest R Cho K Daoudi M Ford WT Johnson DR Lingel K Lohner M Rankin P Smith JG Alexander JP Bebek C Berkelman K Besson D Browder TE Cassel DG Cho HA Coffman DM Drell PS Ehrlich R Galik RS Garcia-Sciveres M Geiser B Gittelman B Gray SW Hartill DL Heltsley BK Jones CD Jones SL Kandaswamy J Katayama N Kim PC 《Physical review D: Particles and fields》1994,49(11):5690-5700
75.
Vladimir V. Bazhanov Sergei L. Lukyanov Alexander B. Zamolodchikov 《Communications in Mathematical Physics》1996,177(2):381-398
We construct the quantum versions of the monodromy matrices of KdV theory. The traces of these quantum monodromy matrices, which will be called as “T-operators,” act in highest weight Virasoro modules. TheT-operators depend on the spectral parameter λ and their expansion around λ=∞ generates an infinite set of commuting Hamiltonians of the quantum KdV system. TheT-operators can be viewed as the continuous field theory versions of the commuting transfermatrices of integrable lattice theory. In particular, we show that for the values $c = 1 - 3\frac{{3(2n + 1)^2 }}{{2n + 3}}$ ,n=1,2,3 .... of the Virasoro central charge the eigenvalues of theT-operators satisfy a closed system of functional equations sufficient for determining the spectrum. For the ground-state eigenvalue these functional equations are equivalent to those of the massless Thermodynamic Bethe Ansatz for the minimal conformal field theoryM 2,2n+3; in general they provide a way to generalize the technique of the Thermodynamic Bethe Ansatz to the excited states. We discuss a generalization of our approach to the cases of massive field theories obtained by perturbing these Conformal Field Theories with the operator Φ1,3. The relation of theseT-operators to the boundary states is also briefly described. 相似文献
76.
It is known that the subgroup growth of finitely generated linear groups is either polynomial or at least $n^{\frac{{\log n}}{{\log \log n}}} $ . In this paper we prove the existence of a finitely generated group whose subgroup growth is of type $n^{\frac{{\log n}}{{(\log \log n)^2 }}} $ . This is the slowest non-polynomial subgroup growth obtained so far for finitely generated groups. The subgroup growth typen logn is also realized. The proofs involve analysis of the subgroup structure of finite alternating groups and finite simple groups in general. For example, we show there is an absolute constantc such that, ifT is any finite simple group, thenT has at mostn c logn subgroups of indexn. 相似文献
77.
Alexander Kreuzer 《Geometriae Dedicata》1996,61(3):279-283
Let (P,
) and (P,
) be linear spaces satisfying the exchange axiom with dim P=dim P . Then a bijection :PP which maps collinear points onto collinear points is an isomorphism. Also a surjection :PP which maps any three non-collinear points to non-collinear points is an isomorphism. This assertion is not true if dim P is not finite. 相似文献
78.
Under certain conditions, we show the nonexistence ofan element in the p-th cyclotomicfield over , that satisfies
. As applications, we establish the nonexistence ofsome difference sets and affine difference sets. 相似文献
79.
Alexander Kreuzer 《Journal of Geometry》1996,56(1-2):87-98
We give a complete and short proof of KAHN's Theorem that every locally projective space (M,M) with dim M3 satisfying the Bundle Theorem is embeddable in a projective space. The central tool of KAHN's proof is the fact that (M,M) is locally projective, while we use mainly the Bundle Theorem.Dedicated to Professor Dr. H. Mäurer on the occasion of his sixtieth birthday 相似文献
80.
Asner DM Athanas M Bliss DW Brower WS Masek G Paar HP Gronberg J Korte CM Kutschke R Menary S Morrison RJ Nakanishi S Nelson HN Nelson TK Qiao C Richman JD Roberts D Ryd A Tajima H Witherell MS Balest R Cho K Ford WT Lohner M Park H Rankin P Smith JG Alexander JP Bebek C Berger BE Berkelman K Bloom K Browder TE Cassel DG Cho HA Coffman DM Crowcroft DS Dickson M Drell PS Dumas DJ Ehrlich R Elia R Gaidarev P Garcia-Sciveres M Gittelman B Gray SW Hartill DL Heltsley BK Henderson S Jones CD 《Physical review D: Particles and fields》1996,53(3):1039-1050